Let me chime in with those people who thoroughly enjoyed this episode.
Why?
Well, part of it was seeing the perspective of someone who's life the Doctor has touched tangentially. I mean, I found that I really liked Elton. I liked his friends (although we saw less of them), and I liked their ordinary-ness.
I enjoy watching Doctor Who with my 7-year-old daughter, and we both enjoyed the Scooby Doo element with the initial alien (the thing that seemed similar to a Weevil, but was not). I liked the mention of the "living shadow from the howling lands" (best use of a D&D monster in a Doctor Who episode, IMHO). Best use of the Innuendo skill when Elton suggests that he has a "sort of a love life" with Ursula's petrified face (shades of The Five Doctors, btw). And while the Fat Bastard rip-off of a final monster was anti-climactic, the monster wasn't really the point.
The point, to me, was Elton's humanity, his willingness to sacrifice, his loss, and his ability to survive and prosper despite that (partial) loss. It was also, of couse, a foreshadowing of the season finale.
Not a deep episode, but a fun episode. One of my favorites from this season.....along with The Impossible Planet/The Satan Pit, School Reuinion, and (#1) The Girl in the Fireplace.